Piston ring



Aug. 21, 1934. R. E. KIRN ET AL PISTON RING Filed March 21, 1952 2 Sheets-Sheet l Aug. 21, 1934.

R. E. KIRN ET AL 1,970,892

PISTON RING Filed March 21, 1952 2 Sheets-Sheet 2 Fig- 2 Patented Aug. 21, 1934 p v I UNITED STATES PATENT OFFICE ris'ron RING Robert E. Kirn, New York, N. Y., and Fred D. Durham, Louisville, Ky., assignors to 0. Lee Cook Manufacturing Company, Louisville, Ky., a corporation of Kentucky Application March 21, 1932, Serial No. 000,314 1 Claim. (cl. soc-29) In a patent numbered 1,741,849 granted on Figure 10 is a bottom plan view of the outer December 31, 1929, there is disclosed a piston or packing ring member the structure shown ring structure in which the outer or packing ring in Figures 8 and 9. member has its joint sealed while the joint of the Figure 11-is a top plan view of the inner or w inner ring or expansion member is allowed to expansion ring member of the structure shown 001 remain open for the entrance of fluid under pres in Figures 8 and 9. sure behind the ring, the structure being such In the form of construction shown in Figures that leakage through the outer ring is prohibited 1-'! inclusive, an outer or packing ring member and the two members or the ring assembly being 12 and an inner or expansion ring member 13 so constructed that in cross section they have constitute the assembly. The outer ring member equal strength and this strength is suillcient to comprises a body 14 having an annular inwardly prevent the several members from being bulged. extending flange 1-5. The ring is split or prooutwardlyinto. the cylinder ports. vided with a joint shown at 16, the ring being While the patented structure is ordinarily adeyieldingly expansible as is well understood to s quate ior that purpose, in the case of a slow-actthose skilled in the art. To

ing machine or where the outer or packing ring The inner or expansion ring member 13 has a member ly r st rs with a cylinder p t or body 1'1. which is located within the body 14 or when operating under extremely high pressures, the outer or packing ring member, and the flange it has been found that there is still the possibility 15 of said outer ring overlies said body 17. This 1; of this member or its ends being bulged into said inner ring body 17 has an outstanding annular 15' cylinder ports as the ring is not under conflneflange 18 which underlies the body portion 18 o! ment. the outer ring member. The inner ring member The object of the present invention is to soimis also split or has a joint as shown at 19 and prove the structure that an effective seal is seth flange 1a is cut away or terminates short of cured, and at the same time the ends of the ring this joint, as shown at 20, thus leaving a recess member that are under compression or are outr e t on opposite sides of the joint '19. In wardly movable due to the inherent expansive th words, the body portion 170! the inner qualiti s of the in a e p p y d against 01 expansion ring is unflanged on opposite sides such movement by the sealing means. pf t i joint 19, t. In he ac mpa ying drawings: Located in this seat or agalnstthe outer side Flame 1 s a on tud a Sectional view or the unnaneed end portionszl oi the body 11 through a po tio of t y i e showing a oi the inner ring member is a tongue 22 formed t n th ein and i ust a in tw of t Pa by an extension ot the body 14 of the outer ring 11118 in pl member, this tongue having a width equal to the Fi ure 2 is a perspective view of one o! the width of the'flange la and a depth also equal P k r1118 assembliesto said flange. Asclearly shown in Figure 2 the Flam 3 is a sectional e on the n tongue 22 thus bridges the joint 19 or the inner 01 F r 2- i or expansion ring member and constitutes aseal Figure 4 is a bottom plan view of the outer or over the otherwise open joint, on the other hand,

0 packing ring member. as shown in Figures 1, 2, 3 and 'l the joint 16 of 96 Figure 5 is a top plan view of the irmer or the outer packing ring member 1 (men so t t xp n ring b when the ring assembly is in place in 'a piston Figure 6 is a detail perspective view 9! the joint and the piston is in 3, i d as exaggeratedly of the exp i n r n and the tongue Portion 0! indicated in Figure 'I, fluid under pressure act- 6 the packing rin the p r being D ing on the top of the piston can find its way 100 m n i a detail sectional view illustrating alongside the piston to the joint 16 and enter the manner in which the fluid under pressure into the piston groove behind t ring The other fi d entrance behind the ring and is retained joint is, however, is completely sealed so that no thereby. fluid can pass therethrough. By reference to Fige 28 is a p rsp ct v v w of s modified ure lit will be clear that ii the ring should pass loo tom of construction in which the ring is subacross or arrive at an exhaust port, as shown at stantially sealed against the entrance 0! fluid 23, it the outer ring member is still engaged with under pressure behind it. the wall oi the cylinder, it is positively held Figure 9 is a sectional view on the line 9-9 against outward movement because it is contina of i 8. uous, and moreover the ireeends 21 of the inner ring being bridged by the tongue 22 and the bodyl'lofthisringmemberisrestrainedonbody portion 16 of the outer ring member, said inner ring is positively held against expansion andis 8 prevented from bulging into port 23, and thus tbfiing or broken by contact with the walls The pressure of the fluid in the groove back of the 'ring against the outer or packing ring mem- 10 her 12 is released through joint opening 16 and the groove clearance as this ring registers with a port 23, but as an extra precaution to neutralize the outward pressure of the fluid ainst the outer or 16 while-saidringisinthe process of with a port and discharging the saidfluid pressure behind the outer ring, the edge or comer" of this particular member is preferably beveled or rounded as shown at 24, which gives access to 20 the fluid under pressure to the outer side of the ring member, and thus obviously neutralizes to the extent of exposure of the outer surface an equal area of the inner surface. This is found peculiarly eflective in the structure disclosed. The embodiment shown in Figures 8-11 inclusive is particularly useful where high pressures are employed and it is undesirable to allow such .pressurestoobtainbehindthering. Inthisform of structure, both the Joints of the inner and outer wiring members are completely sealed so that the onlyfluidwhichcanflndaccesstotheinner side'of the ring assembly is that which through the i s but very small clearance of the ring assembly in'its groove. as. In this modifled structure the inner ring member is designated 25 and is-provided with a cut or Joint 26. Said ring member has an outstanding annular flange 27 which terminates at points spaced from the joint 28,-leaving the ends 28 eiiflmflanged. The outer or packing ring member is d signated 29, and has a cut or Joint 30. It

packing ring member 12,

is provided with an inset annular flange 31, the ends ofwhich terminate at points remote from the ends of the ring body proper, so that the terminal portions 32 of this ring member 29 are unflanged (see Figure 10). The inner ring member 25 isprovided at its central portion with a sealing tongue 83 which bridges thefjointj'or cut 30 of the ring 29 and is located betwenthe ends of the flange 31, acting as a complete seal for the joint 30. In like manner the central portion of the ring 29 has a tongue 34 that correspondingly covers the joint 26 and overlies the unflanged ends 28 of the ring 25. Thus, as will be evident by reference particularly to Figures 8 and 9 the open cuts or joints of both members are completely sealed and there is no freely open channel or passageway that gives ac? cess of fluid under pressure to the interior of the What we claim is: v I

A piston ring assembly including a packing ring member, and an expansion ring member, said expansion ring member comprising a split body hav-, ing an annular outstanding flange that is on posite sides of the split, leaving unflanged terminals of the body on, opposite sides of the split,-. said packing ring member having a split body portion extending around the outer side of the en. pension ring at one side of the flange thereof and having an oflset tongue that extends between the ends of the flange of the expansion ring meme -ber the full width of the expansion ring: and."

bridges and seals the cut or Joint between the flanged terminals of the body of the expansion ring member, said expansion ring leaving. the m joint of the packing ring member unsealed to provide'a port for the admission of fluid under pres-:\

sure behind the piston ring assembly.

nbnnn'rn. .1 FRED D. DURHAM. 

